#!/bin/sh

# Copyright (C) 2022 Internet Systems Consortium, Inc. ("ISC")
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

# shellcheck disable=SC1091
# SC1091: Not following: ... was not specified as input (see shellcheck -x).

# Exit with error if commands exit with non-zero and if undefined variables are
# used.
set -eu

# shellcheck disable=SC2034
# SC2034: ... appears unused. Verify use (or export if used externally).
prefix="/usr"

# Include utilities. Use installed version if available and
# use build version if it isn't.
if [ -e ${prefix}/share/kea/scripts/admin-utils.sh ]; then
    . "${prefix}/share/kea/scripts/admin-utils.sh"
else
    . "/build/kea/src/kea-2.2.0/src/bin/admin/admin-utils.sh"
fi

VERSION=$(pgsql_version "$@")

if [ "$VERSION" != "9.0" ]; then
    printf 'This script upgrades 9.0 to 10.0. '
    printf 'Reported version is %s. Skipping upgrade.\n' "${VERSION}"
    exit 0
fi

psql "$@" >/dev/null <<EOF
START TRANSACTION;

-- This starts schema update to 10.0.
-- It adds corrections for client classes for CB

-- Replace setClientClass4Order():
-- 1. l_depend_on_known_indirectly needs to be BOOL
-- 2. follow_class_index needs to be BIGINT

-- -----------------------------------------------------------------------
-- Stored procedure positioning an inserted or updated client class
-- within the class hierarchy, depending on the value of the
-- new_follow_class_name parameter.
--
-- Parameters:
-- - id id of the positioned class,
-- - new_follow_class_name name of the class after which this class should be
--   positioned within the class hierarchy.
-- - old_follow_class_name previous name of the class after which this
--   class was positioned within the class hierarchy.
-- -----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION setClientClass4Order(id BIGINT,
                                                new_follow_class_name VARCHAR(128),
                                                old_follow_class_name VARCHAR(128))
RETURNS VOID
LANGUAGE plpgsql
AS \$\$
DECLARE
    -- Used to fetch class's current value for depend_on_known_indirectly
    l_depend_on_known_indirectly BOOL := false;

    -- Optionally set if the follow_class_name column value is specified.
    follow_class_index BIGINT;
BEGIN
    -- Fetch the class's current value of depend_on_known_indirectly.
    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
        FROM dhcp4_client_class_order WHERE id = class_id;

    -- Save it to the current session for use elsewhere during this transaction.
    -- Note this does not work prior to Postgres 9.2 unless the variables are
    -- defined in postgresql.conf. I think for now we put up with CB not supported
    -- prior to 9.2 or we tell people how to edit the conf file.
    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);

    -- Bail if the class is updated without re-positioning.
    IF(
       l_depend_on_known_indirectly IS NOT NULL AND
       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
        (new_follow_class_name = old_follow_class_name))
    ) THEN
        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
        -- whenever the dhcp4_client_class record is updated. Such update may include
        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
        -- This value will be later adjusted when dependencies are inserted.
        -- TKM should we update the session value also or is it moot?
        UPDATE dhcp4_client_class_order SET depend_on_known_indirectly = false
            WHERE class_id = id;
        RETURN;
    END IF;

    IF new_follow_class_name IS NOT NULL THEN
        -- Get the position of the class after which the new class should be added.
        SELECT o.order_index INTO follow_class_index
            FROM dhcp4_client_class AS c
            INNER JOIN dhcp4_client_class_order AS o
                ON c.id = o.class_id
            WHERE c.name = new_follow_class_name;

        IF follow_class_index IS NULL THEN
            -- The class with a name specified with new_follow_class_name does
            -- not exist.
            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
                USING ERRCODE = 'sql_routine_exception';
        END IF;

        -- We need to place the new class at the position of follow_class_index + 1.
        -- There may be a class at this position already.
        IF EXISTS(SELECT * FROM dhcp4_client_class_order WHERE order_index = follow_class_index + 1) THEN
            -- There is a class at this position already. Let's move all classes
            -- starting from this position by one to create a spot for the new
            -- class.
            UPDATE dhcp4_client_class_order
                SET order_index = order_index + 1
            WHERE order_index >= follow_class_index + 1;
            -- TKM postgresql doesn't like order by here, does it matter?
            -- ORDER BY order_index DESC;
        END IF;

    ELSE
        -- A caller did not specify the new_follow_class_name value. Let's append the
        -- new class at the end of the hierarchy.
        SELECT MAX(order_index) INTO follow_class_index FROM dhcp4_client_class_order;
        IF follow_class_index IS NULL THEN
            -- Apparently, there are no classes. Let's start from 0.
            follow_class_index = 0;
        END IF;
    END IF;

    -- Check if moving the class doesn't break dependent classes.
    IF EXISTS(
        SELECT 1 FROM dhcp4_client_class_dependency AS d
            INNER JOIN dhcp4_client_class_order AS o
                ON d.class_id = o.class_id
            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
        LIMIT 1
    ) THEN
        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
            USING ERRCODE = 'sql_routine_exception';
    END IF;

    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
    -- whenever the dhcp4_client_class record is updated. Such update may include
    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
    -- This value will be later adjusted when dependencies are inserted.
    -- TKM - note that ON CONFLICT requires PostgreSQL 9.5 or later.
    UPDATE dhcp4_client_class_order
        SET order_index = follow_class_index + 1,
            depend_on_known_indirectly = l_depend_on_known_indirectly
        WHERE class_id = id;
    IF FOUND THEN
        RETURN;
    END IF;

    INSERT INTO  dhcp4_client_class_order(class_id, order_index, depend_on_known_indirectly)
        VALUES (id, follow_class_index + 1, false);
    RETURN;
END;\$\$;

-- Replace setClientClass6Order():
-- 1. l_depend_on_known_indirectly needs to be BOOL
-- 2. follow_class_index needs to be BIGINT

-- -----------------------------------------------------------------------
-- Stored procedure positioning an inserted or updated client class
-- within the class hierarchy, depending on the value of the
-- new_follow_class_name parameter.
--
-- Parameters:
-- - id id of the positioned class,
-- - new_follow_class_name name of the class after which this class should be
--   positioned within the class hierarchy.
-- - old_follow_class_name previous name of the class after which this
--   class was positioned within the class hierarchy.
-- -----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION setClientClass6Order(id BIGINT,
                                                new_follow_class_name VARCHAR(128),
                                                old_follow_class_name VARCHAR(128))
RETURNS VOID
LANGUAGE plpgsql
AS \$\$
DECLARE
    -- Used to fetch class's current value for depend_on_known_indirectly
    l_depend_on_known_indirectly BOOL := false;

    -- Optionally set if the follow_class_name column value is specified.
    follow_class_index BIGINT;
BEGIN
    -- Fetch the class's current value of depend_on_known_indirectly.
    SELECT depend_on_known_indirectly INTO l_depend_on_known_indirectly
        FROM dhcp6_client_class_order WHERE id = class_id;

    -- Save it to the current session for use elsewhere during this transaction.
    -- Note this does not work prior to Postgres 9.2 unless the variables are
    -- defined in postgresql.conf. I think for now we put up with CB not supported
    -- prior to 9.2 or we tell people how to edit the conf file.
    PERFORM set_session_value('kea.depend_on_known_indirectly', l_depend_on_known_indirectly);

    -- Bail if the class is updated without re-positioning.
    IF(
       l_depend_on_known_indirectly IS NOT NULL AND
       ((new_follow_class_name IS NULL AND old_follow_class_name IS NULL) OR
        (new_follow_class_name = old_follow_class_name))
    ) THEN
        -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
        -- whenever the dhcp6_client_class record is updated. Such update may include
        -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
        -- This value will be later adjusted when dependencies are inserted.
        -- TKM should we update the session value also or is it moot?
        UPDATE dhcp6_client_class_order SET depend_on_known_indirectly = false
            WHERE class_id = id;
        RETURN;
    END IF;

    IF new_follow_class_name IS NOT NULL THEN
        -- Get the position of the class after which the new class should be added.
        SELECT o.order_index INTO follow_class_index
            FROM dhcp6_client_class AS c
            INNER JOIN dhcp6_client_class_order AS o
                ON c.id = o.class_id
            WHERE c.name = new_follow_class_name;

        IF follow_class_index IS NULL THEN
            -- The class with a name specified with new_follow_class_name does
            -- not exist.
            RAISE EXCEPTION 'Class %s does not exist.', new_follow_class_name
                USING ERRCODE = 'sql_routine_exception';
        END IF;

        -- We need to place the new class at the position of follow_class_index + 1.
        -- There may be a class at this position already.
        IF EXISTS(SELECT * FROM dhcp6_client_class_order WHERE order_index = follow_class_index + 1) THEN
            -- There is a class at this position already. Let's move all classes
            -- starting from this position by one to create a spot for the new
            -- class.
            UPDATE dhcp6_client_class_order
                SET order_index = order_index + 1
            WHERE order_index >= follow_class_index + 1;
            -- TKM postgresql doesn't like order by here, does it matter?
            -- ORDER BY order_index DESC;
        END IF;

    ELSE
        -- A caller did not specify the new_follow_class_name value. Let's append the
        -- new class at the end of the hierarchy.
        SELECT MAX(order_index) INTO follow_class_index FROM dhcp6_client_class_order;
        IF follow_class_index IS NULL THEN
            -- Apparently, there are no classes. Let's start from 0.
            follow_class_index = 0;
        END IF;
    END IF;

    -- Check if moving the class doesn't break dependent classes.
    IF EXISTS(
        SELECT 1 FROM dhcp6_client_class_dependency AS d
            INNER JOIN dhcp6_client_class_order AS o
                ON d.class_id = o.class_id
            WHERE d.dependency_id = id AND o.order_index < follow_class_index + 1
        LIMIT 1
    ) THEN
        RAISE EXCEPTION 'Unable to move class with id %s because it would break its dependencies', id
            USING ERRCODE = 'sql_routine_exception';
    END IF;

    -- The depend_on_known_indirectly is set to 0 because this procedure is invoked
    -- whenever the dhcp6_client_class record is updated. Such update may include
    -- test expression changes impacting the dependency on KNOWN/UNKNOWN classes.
    -- This value will be later adjusted when dependencies are inserted.
    -- TKM - note that ON CONFLICT requires PostgreSQL 9.5 or later.
    UPDATE dhcp6_client_class_order
        SET order_index = follow_class_index + 1,
            depend_on_known_indirectly = l_depend_on_known_indirectly
        WHERE class_id = id;
    IF FOUND THEN
        RETURN;
    END IF;

    INSERT INTO  dhcp6_client_class_order(class_id, order_index, depend_on_known_indirectly)
        VALUES (id, follow_class_index + 1, false);
    RETURN;
END;\$\$;

-- Change primary key to composite, dependency table can have multiple rows
-- per class id.
ALTER TABLE dhcp4_client_class_dependency DROP CONSTRAINT dhcp4_client_class_dependency_pkey;
ALTER TABLE dhcp4_client_class_dependency ADD PRIMARY KEY(class_id, dependency_id);

ALTER TABLE dhcp6_client_class_dependency DROP CONSTRAINT dhcp6_client_class_dependency_pkey;
ALTER TABLE dhcp6_client_class_dependency ADD PRIMARY KEY(class_id, dependency_id);

-- Replace triggers that verify class dependency.
-- Because they are BEFORE INSERT triggers they need to return NEW not NULL.
-- -----------------------------------------------------------------------
-- Trigger verifying if class dependency is met. It includes checking
-- if referenced classes exist, are associated with the same server
-- or all servers, and are defined before the class specified with
-- class_id.
-- -----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION func_dhcp4_client_class_check_dependency_BINS()
    RETURNS trigger AS \$dhcp4_client_class_check_dependency_BINS\$
BEGIN
    PERFORM checkDHCPv4ClientClassDependency(NEW.class_id, NEW.dependency_id);
    RETURN NEW;
END;
\$dhcp4_client_class_check_dependency_BINS\$
LANGUAGE plpgsql;

-- -----------------------------------------------------------------------
-- Trigger verifying if class dependency is met. It includes checking
-- if referenced classes exist, are associated with the same server
-- or all servers, and are defined before the class specified with
-- class_id.
-- -----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION func_dhcp6_client_class_check_dependency_BINS()
    RETURNS trigger AS \$dhcp6_client_class_check_dependency_BINS\$
BEGIN
    PERFORM checkDHCPv6ClientClassDependency(NEW.class_id, NEW.dependency_id);
    RETURN NEW;
END;
\$dhcp6_client_class_check_dependency_BINS\$
LANGUAGE plpgsql;

-- Update the schema version number.
UPDATE schema_version
    SET version = '10', minor = '0';

-- Commit the script transaction.
COMMIT;

EOF
